(a) Technical Field
The invention relates to a display device and control method thereof.
(b) Description of the Related Art
In general, stereo viewing (e.g. 3-D (3-dimensional) image, etc.) involves a display of separate content for the right and left eye. Specifically, stereo viewing requires the presentation of a separate image to the left and right eye. The left and right images of stereo viewing are presented in an alternating manner. Conventional CRT monitor and related displays use progressive scan along scan lines in a frame. CRT monitor controls shutter glasses for the left and right eye to alternately switch between a closed orientation and an open orientation so as to make the left image visible to the left eye and the right image to the right eye at appropriate time during progressive scan. Thus, CRT monitor and related displays may ensure a proper stereo viewing experience.
However, stereo viewing has not shown promise with liquid crystal display (LCD), whether flat-panel or in the form of a projector. Such left and right images being presented in an alternating manner, in a type of stereo viewing, is namely time sequential stereo. Time sequential stereo needs to update image frame sequentially in a monitor. Therefore, if the display control method for alternating shutter glasses of CRT monitor is adopted by LCD, it may cause ‘ghosting’ of the left image in the right view and vice versa due to a slow response time of pixels in LCD.
A prior US patent publication Ser. No. US2001/0029395 A1 discloses a method to overcome an unacceptable stereo viewing experience of LCD. The prior method controls a right eye shutter and left eye shutter of the shutter glasses simultaneously remain in the closed orientation in image update duration. Then, the prior method controls shutter glasses to be an open orientation for a predetermined eye until a full image of display content for such eye is available during a vertical blanking interval. Specifically, a left eye shutter is controlled to be an open orientation for the duration of a first vertical blanking interval, which follows receipt of display content intended for a left eye; and a right eye shutter is controlled to be an open orientation for the duration of a second vertical blanking interval, which follows receipt of display content intended for a right eye. The prior method needs to enlarge the vertical blanking interval so as to buffer display content received from a content source longer. Consequently, a new timing specification including enlarged vertical blanking interval needs to be designed for a display controller or a panel.
As stated above, prior 3-D image display method needs to use a specially made timing to control a monitor or a panel. If the prior method is introduced, manufacturers need to redesign circuitries of a display controller or a panel conforming to the specially made timing. Thus, elements can not be shared between displays or panels due to different specification of display control mechanism to thereby increase cost of stock and inventory of manufacturers.